JPH0328014Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a technology for a multiphase flow transport device (pneumatic transport device) that transports powder and granules into a pipe using a fluid with a pressure higher than atmospheric pressure. The present invention is used in the field, and specifically relates to improvements in ejectors that smoothly transport powder and granular materials.

[Conventional technology]

In a multiphase flow transport device that performs pneumatic transport by supplying powder and granules into a transport pipe through which compressed air flows using a feeder such as a rotary feeder, the pressure of the fluid (compressed air) when transporting powder and granules is However, when the transportation pressure is high, it is not possible to maintain smooth supply, and supply is often impossible. had been experienced.

Therefore, as one of the countermeasures against such a case, an ejector-type air transport device having a structure in which a compressed air injection nozzle is provided in the lower transport pipe of the supply device has been used.

FIG. 3 shows an example of the ejector-type pneumatic transport device described above, which uses a rotary leaf feeder R as a powder feeder and has a compressed air injection nozzle N inside the lower transport pipe P of the rotary leaf feeder R. In the cross-sectional view shown, when compressed air is injected from the injection nozzle N while rotating the rotary feeder R in the direction of the arrow and supplying the granular material M, at the tip of the nozzle N according to Bernoulli's theorem, Since the static pressure of the airflow decreases, the powder and granular material M falling and supplied from the upper rotary feeder R is easily blown away and mixed into the airflow, thereby causing the powder and granular material M to enter the transport pipe P. The system is designed to enable smooth supply.

[Problem that the invention attempts to solve]

However, in the ejector type pneumatic transport device having the above configuration, in order to reduce the backflow phenomenon of compressed air to the rotary leaf feeder R and reliably supply the powder and granular material M,
In order to increase the velocity of the airflow at the tip of the injection nozzle N, it was necessary to select the diameter of the injection nozzle N to a size suitable for this purpose.

That is, in a low-pressure pressure-feeding air transportation device that uses a turbo blower or Roots blower as a supply source of compressed air to the injection nozzle N, or in a high-pressure pressure-feeding air transportation device that uses a reciprocating motion or screw type air compressor as a supply source of compressed air, In general, the air velocity at the tip of the injection nozzle N is set to a high velocity of several + m/s or more to the speed of sound, on the premise that the accompanying pressure loss is within a range that can be tolerated by the device. was.

Therefore, in order to reliably supply the granular material M to the transport pipe P side, it is desirable to increase the air velocity at the tip of the injection nozzle N as much as possible, but on the other hand, the faster the air velocity is There were problems in that the device suffered a considerable pressure loss, resulting in excessive power consumption, and that particles of the transported material were crushed by the transport air that was injected at high speed.

Therefore, the technical problem of this invention is to reduce the backflow of compressed air to the powder/granular material feeder, reduce the pressure loss of the transport air, and ultimately reduce the power consumption for compressed air injection, and supply the powder/granular material. The objective is to minimize the crushing of transported particles by smoothing the process.

[Means for solving problems]

The measures taken in the present invention to solve the above technical problems are as follows.

(1) At the tip of the compressed air injection nozzle installed in the lower transport pipe of the powder supply device, connect a tapered pipe that gradually widens in diameter in the direction of the compressed air injection direction.

(2) Multiple penetration holes for the powder and granular material shall be drilled on the circumferential surface of the tapered pipe.

However, the term "powder feeder" as used herein refers to a device that supplies a fixed amount of the powder supplied to the hopper to the transport pipe using a rotary feeder, pressurized air, etc. is a low-pressure air supply device such as a turbo blower or roots blower,
Alternatively, it refers to transport air supplied toward the injection nozzle from a high-pressure pumping air supply device such as a reciprocating type or a screw type.

[Effect]

The above means works as follows.

The element (1) above is such that the compressed air injected from the tip of the injection nozzle is guided through the tapered pipe connected to the tip and injected in the transport direction of the transport pipe. It is possible to reduce the backflow of compressed air against the powder and to smoothly supply powder and granular material.

The above factor (2) is because the powder and granules supplied from the supply device are dispersed through the entry holes drilled in the tapered pipe and sucked into the tapered pipe by the suction action of the jet of compressed air from the injection nozzle. Since the powder and granules do not concentrate at the jet nozzle, and can be dispersed and mixed in the airflow circle, pressure loss and even power consumption are reduced, and the transport particles are reduced. It also makes it possible to reduce the degree of crushing.

As described above, the above-mentioned technical problem can be solved by the above-mentioned means, and the problems of the conventional technology can be solved.

〔Example〕

Hereinafter, preferred embodiments of the ejector for transporting powder and granular materials according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing an example of a pneumatic transportation device embodying the present invention.
A rotary leaf feeder 1 is used as a feeder for supplying powder and granular material M accommodated in a hopper 2, and as the rotary leaf feeder 1 rotates, a fixed amount is supplied into a transport pipe 3 connected to the lower side. .

Reference numeral 4 denotes an injection nozzle installed in the transport pipe 3, and compressed air is supplied to the injection nozzle 4 from the direction of arrow X. Reference numeral 5 denotes a tapered pipe connected to the tip opening 4a of the injection nozzle 4, and the tapered pipe 5 is formed in a substantially tupular shape that gradually widens in diameter toward the injection direction of the compressed air, that is, the direction of transport of the granular material M. It is being In addition, 6... are penetration holes for the powder or granular material M drilled on the circumferential surface of the tapered pipe 5, and the circumferential surface portion of the tapered tube 5 where these penetration holes 6... are bored is exactly the same as that of the feeder 1. It is configured to be located on the lower side.

Since the ejector for transporting powder and granular materials according to the present invention has the configuration as described above, the rotary feeder 1
When supplying compressed air while supplying a fixed amount of granular material M by rotating in the direction of the arrow, the transport air is injected from the tip port 4a of the injection nozzle 4 through the tapered pipe 5 into the transport pipe 3. . Then, a suction force acts inside the tapered tube 5, and the powder M supplied in a fixed amount from the rotary leaf feeder 1 is transferred to each entry hole 6...
By dispersing and suctioning the particles, it becomes possible to uniformly mix the dispersed and suctioned powder particles M into the airflow of the transport air.

〔effect〕

Therefore, according to the ejector for transporting powder or granular material according to the present invention, the powder or granular material does not concentrate at the tip orifice of the injection nozzle, as seen in the conventional ejector system shown in FIG. Since it can be transported evenly mixed in the transport air, pressure loss is minimized and power consumption is reduced, and pneumatic transport can be carried out in a stable and economical manner. It also has the advantage of being able to transport particles smoothly with less crushing, and is particularly suitable for use in transporting granular materials that are relatively soft and easily crushed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a low-pressure pressure-feeding pneumatic transportation device incorporating an ejector according to the present invention, FIG. 2 is a perspective view of an injection nozzle that constitutes the main part of the present invention, and FIG. FIG. 2 is a sectional view of a conventional device. 1 is a rotary feeder (powder feeder), 3
4 is a transport pipe, 4 is an injection nozzle, 4a is a tip opening, 5 is a tapered pipe, 6 is an entry hole, and M is a granular material.

Claims (1)

[Scope of utility model registration request] In a multiphase flow transport device, an air injection nozzle is provided in the lower transport pipe of a powder supply device, and the powder is transported by compressed air ejected from the nozzle.
A tapered pipe whose diameter gradually increases in the direction of the compressed air jet is connected to the tip of the nozzle, and a plurality of entry holes for the powder and granular material are bored around the tapered pipe. Ejector for transporting powder and granular materials.